Material dispensing apparatus

ABSTRACT

An apparatus for dispensing fine particulate material includes a hopper for storing material to be dispensed, a discharge tube having a discharge nozzle and an auger for feeding stored material from the hopper to the discharge tube. The fine particulate material is regulated by a meter which meters the amount transferred by the auger to the discharge tube. Material is transferred to a container to be charged by positioning it against the discharge nozzle so that the auger transfers a predetermined amount of material from the hopper to the discharge tube. Material laden displaced air from the container escapes into a settling tube where the material in the displaced air is allowed to settle and fall by gravity into the container.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a dispensing apparatus and moreparticularly relates to an apparatus for dispensing fine particulatematerial such as toner for photocopiers and laser printers. "Toner" is aterm used in reprographics to describe the electrostatic compound thatacts as the "ink" forming the image on a plain-paper copy.

2. Description of the Prior Art

Fine particulate material is known to be difficult to handle inautomated processes. This is particularly true where the material is tobe passed from one container to another. Where material is passed fromone container to another, displaced air carries with it a certain amountof the fine material. This arrangement is often unsatisfactory as itcreates a particle-laden atmosphere which may be hazardous to breathe.Additionally, accumulated material may effect machinery and may bedifficult to clean.

In a known semi-automated process such as that exemplified by Per-Filapparatus (Per-Fil Industries, Inc. Riverside, N.J. 08075, U.S.A.), fineparticulate material is dispensed from a storage hopper into cartridgesfor use. The material is toner for laser printers, photocopiers and thelike, and is used for charging cartridges which fit specific machines.The dispensing apparatus is required to meter out a predetermined amountof toner into a range of sizes of toner cartridge and comprises ahopper, a vertically disposed auger and a dispensing nozzle. In thisfilling process, the empty cartridge is held under the dispensing tofeed the required amount of material to the nozzle. The displaced aircarries with it a quantity of toner. Additionally, due to theliquid-like flow of fine particulate material, the amount of tonerdispensed from the auger may vary unacceptably.

SUMMARY OF THE INVENTION

It is a object of the present invention to seek to alleviate the abovedisadvantages and to provide an improved dispensing apparatus for fineparticulate material such as toner.

Accordingly, the present invention provides an apparatus for dispensingfine particulate material comprising:

a hopper for storing material to be dispensed;

a discharge tube having a discharge nozzle;

a generally horizontally disposed feeding means for transferring storedmaterial from the hopper to the discharge tube;

a fine particulate material metering means for regulating the amount ofmaterial transferred by the feeding means to the discharge tube;

a settling tube; and

biasing means operable to urge a container to be charged with materialinto sealing engagement with the discharge nozzle,

whereby in use the container is sealed against the discharge nozzle, thefeeding means transfers a predetermined amount of material from thehopper to the discharge tube and material laden displaced air from thecontainer escapes into the settling tube where the material in thedisplaced air settles and falls by gravity into the container

Preferably, the feeding means comprises a generally horizontallydisposed auger.

Advantageously, the auger is arranged so that the particulate materialcarried therethrough is biased to remain in the auger or to return tothe hopper, whereby flow of the material ceases when the auger stops.

Conveniently, the metering means comprises a timer based switching meansto regulate the number of revolutions of the auger so that the materialthrough-feed is accurately and consistently metered.

In a preferred embodiment, the discharge tube and the settling tube formpart of a vertically disposed tube which is fed by the auger at ajunction located remote from the tube's upper end. The material fallsfrom the junction to the discharge nozzle at the lower end of the tubeand displaced air escapes upwardly via the discharge tube to thesettling tube where the material carried by the displaced air is allowedto settle and fall under gravity into the container juxtaposed thedischarge nozzle.

Advantageously, the container is sealed against the discharge nozzle bya plate having the biasing means.

Conveniently, the discharge nozzle has a tapered profile to facilitatesealing engagement with a range of container charging apertures.

Preferably, a means is included for agitating the material in thehopper.

Advantageously, the agitating means is driven from the feeding means.

The apparatus preferably comprises a single hopper (23) and a pluralityof feeding means (25) and associated discharge tubes.

The invention will now be described more particularly with reference tothe accompanying drawings which show, by way of example only, oneembodiment of dispensing apparatus according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation of the dispensing apparatus;

FIG. 2 is a side elevation of the dispensing apparatus; and

FIG. 3 is a sectional side elevation of the apparatus taken along linesIII--III of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings and initially to FIGS. 1 and 2, a dispensingapparatus 10 has two dispensing outlets each comprising a dispensingtube 12 having a dispensing nozzle 13 thereon. Above each dispensingtube 12 is a settling tube 15 which is open-ended to allow air toescape.

The apparatus 10 further comprises a housing 20 which contains a hopper23 and an auger 25 for each dispensing outlet, as shown in detail inFIG. 3. In use a toner cartridge C which is to be charged with toner Tis placed on a spring biased plate 30. The plate has a foam pad 32 toprotect the cartridge C from accidental damage. The cartridge C has acharging aperture which is brought into engagement with the dispensingnozzle 13 which has a tapered profile to provide substantially sealedcontact between the nozzle and the cartridge charging aperture. Acontrol panel 35 is provided for each dispensing outlet. Each controlpanel 35 has an LED or LCD display 36, preprogrammable function keys 37and numerical input keys 38. When a cartridge C is to be charged, theuser selects a function from the panel 35 and presses one of thecorresponding keys 37,38. A motor 40 rotates the auger 25 at a constantspeed for a period determined by the selected input. As the auger 25rotates, toner T from the hopper 23 is fed along the auger 25 until itdrops under gravity into the dispensing tube 12. The toner T flowsthrough the nozzle 13 and into the cartridge C. As the cartridge C fillswith toner T, displaced air is forced back through the nozzle 13. Thedisplaced air carries with it fine particles of toner T' which travelupwardly through the dispensing tube 12 into the settling tube 15. Asthe displaced air becomes less turbulent the toner particles T' begin tosettle and fall back into the dispensing tube 12. The substantiallyclean displaced air escapes through the open top of the settling tube15.

The spring biased plates 30 and the tapered profile of the dispensingnozzle 13 allow a range of cartridges C to be charged. Cartridges withlarge or small capacities can be accurately filled to prespecifiedweights by activating the auger 25 for a period correspondingproportionally to the required weight or volume of toner required.

Accuracy of the amounts of toner dispensed is dependent on the constantspeed rotation of the auger 25 for precisely controlled periods and isalso dependent on the orientation of the auger 25. As the auger ishorizontally disposed, once the auger stops rotating toner supply to thedispensing tube ceases. If, as in the prior art, the dispensing end ofthe auger is significantly lower than the hopper feed end of the augerthen toner flow characteristics affect the accuracy as when the augerstops rotating, toner flow continues in a random manner for a shortperiod. In an alternative embodiment of the present invention, thedispensing end of the auger is significantly higher than the hopper feedend. This embodiment (not shown) allows a greater hopper storagecapacity and preserves the accuracy of material dispensed.

Although the present invention is directed towards a dispensingapparatus for toner for use in printers such as laser printers and inphotocopiers, it will be seen that the apparatus is suitable fordispensing any fine particulate material.

An agitator (not shown) is optionally provided in the hopper 23 toprevent "clumping" of the toner T. The agitator is powered eitherdirectly from the auger 25 or from the motor 40.

The embodiment of the present invention may be adapted for user in amodular form whereby banks of dispensing apparatus may be assembled.

It will of course be understood that the invention is not limited to thespecific details described herein, which are given by way of exampleonly, and that various modifications and alterations are possible withinthe scope of the appended claims.

What is claimed is:
 1. An apparatus for dispensing fine particulatematerial comprising:a hopper for storing material to be dispensed; adischarge tube having a discharge nozzle; a generally horizontallydisposed feeding means for transferring stored material from the hopperto the discharge tube; a fine particulate material metering means forregulating the amount of material transferred by the feeding means tothe discharge tube; a settling tube; and biasing means operable to urgea container to be charged with material into sealing engagement with thedischarge nozzle,whereby in use the container is sealed against thedischarge nozzle, the feeding means transfers a predetermined amount ofmaterial from the hopper to the discharge tube and material ladendisplaced air from the container escapes into the settling tube wherethe material in the displaced air settles and falls by gravity into thecontainer.
 2. A dispensing apparatus as claimed in claim 1, in which thefeeding means comprises a generally horizontally disposed auger.
 3. Adispensing apparatus as claimed in claim 2, in which the auger isarranged so that the particulate material carried therethrough is biasedto remain in the auger or to return to the hopper, whereby flow of thematerial ceases when the auger stops.
 4. A dispensing apparatus asclaimed in claim 2, in which the metering means comprises a timer basedswitching means to regulate the number of revolutions of the auger sothat the material through-feed is accurately and consistently metered.5. A dispensing apparatus as claimed in claim 2, in which the dischargetube and the settling tube form part of a vertically disposed tube whichis fed by the auger at a junction located remote from the tube's upperend.
 6. A dispensing apparatus as claimed in claim 1, in which thecontainer is sealed against the discharge nozzle by a plate having thebiasing means.
 7. A dispensing apparatus as claimed in claim 1, in whichthe discharge nozzle has a tapered profile to facilitate sealingengagement with a range of container charging apertures.
 8. A dispensingapparatus as claimed in claim 1, which includes a means for agitatingthe material in the hopper.
 9. A dispensing apparatus as claimed inclaim 8, in which the agitating means is driven from the feeding means.10. A dispensing apparatus as claimed in claim 1, comprising a singlehopper and a plurality of feeding means and associated discharge tubes.